Automotive systems such as air conditioning systems, power steering systems, and the like employ circulating pressurized fluid. The fluid can become contaminated with small particles, so filter elements, such as thimble filters, sometimes are employed in the fluid path to trap contaminates. One problem with such filters is that they can sometimes become clogged, thereby restricting fluid flow and degrading system performance. Various filter units employing some form of automatic bypass in a clogged filter condition have been employed, but most are complicated and can be unreliable. A need exists for a simple filter system that, when clogged, takes itself out of the fluid flow to prevent constriction or restriction of the flow. It is to the provision of such a filter system that this invention is primarily directed.